package com.yang.springcloud.lb;

import org.springframework.cloud.client.ServiceInstance;
import org.springframework.stereotype.Component;

import java.util.List;
import java.util.concurrent.atomic.AtomicInteger;

/**
 * @Author yang
 * @Date 2022/8/17
 */
@Component
public class MyLB implements LoadBalancer{
    private AtomicInteger atomicInteger = new AtomicInteger(0);

    public final int getAndIncrement(){
       int current;
       int next;
       do {
           current = this.atomicInteger.get();
//           int maxValue = Integer.MAX_VALUE;
           next = current >= 2147483647 ? 0 : current + 1;
       }while (!this.atomicInteger.compareAndSet(current,next));
        System.out.println("****访问次数next:"+next);
        return next;

    }
    //负载均衡算法：rest接口第几次请求数 % 服务器集群总数量 = 实际调用服务器位置下标  ，每次服务重启动后rest接口计数从1开始。
    @Override
    public ServiceInstance instance(List<ServiceInstance> serviceInstanceList) {
        int index = getAndIncrement() % serviceInstanceList.size();
        return serviceInstanceList.get(index);
    }
}
